Safety adapter socket plug for electrical appliances



H. SHAPIRO 2,597,600

APPLIANCES May 20, 1952 SAFETY ADAPTOR SOCKET PLUG FOR ELECTRICAL Filed March 28, 1949 INVENTOR HYMAN SHA mo Patented May 20, 1952 UNITED STATES PATENT OFFICE SAFETY ADAPTER SOCKET PLUG FOR ELECTRICAL APPLIANCES 2 Claims. 1

This invention relates to new and useful improvements in a safety adaptor incorporating a fuse of a desired type, for quick-detachable use either in connection with an electrical appliance or an electrical outlet, for plugging in either at a wall receptacle or the like or at an analogous receptacle carried by the appliance, whereby when there is a short circuit in any part of the appliance, said fuse blows, thereby to prevent the usual blowing of a fuse at a central location and the consequent breaking of current supply throughout an entire wiring system or throughout a subdivision thereof for supplying current not only at said outlet but otherwise throughout said subdivision; and, more particularly, the aim is to provide a novel and valuable such adaptor which is of exceptionally sturdy yet compact construction, which is easily assemblable and at very low cost, and wherein a blown fuse thereof may be readily removed and replaced.

A feature of the invention is the generally elongate nature of the new adaptor structure, adapting the same for easy manual handling, and convenient and desirable placement on an appliance; it being understood that by an appliance is meant not only such a utility as one having electrically operated movable parts, for instance, a vacuum cleaner, but also, for example, an electric iron, a lamp provided merely for illuminating purposes, etc., etc.

A further feature of the new adaptor is a simplified collection of metal or other conductive parts, these including a pair of input prong 01' blade terminals, a pair of outlet clip terminals, a connector element joining a first one of said clip terminals and a first one of said blade terminals and integral with both thereof, a further pair of conductive elements one leading from the second of said clip terminals and for contactive coaction with one end or terminal of the fuse and the other leading from the second of said blade terminals for contactive coaction with the other end or terminal of the fuse; and, in combination with these electrically conductive components, a simplified and improved single insulation-block mounting for them all.

A further feature of the invention is the provision of a simplified and improved protective outer casing or quasi-casing for said block, said casing moldable of insulation material; with the parts so relatively dimensioned and shaped that with said casing securely yet readily detachably in place on said block all electrically conductive elements. except said pair of blade terminals, are properly shielded and fully protectively enclosed.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the following description and accompanying drawings, and to the appended claims in which the various novel fea tures of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a perspective view showing an embodiment of the invention as now favored, and looking toward the side thereof wherefrom are projected the aforesaid blade terminals.

Fig. 2 is a similar view, but looking at the side thereof at which are located two openings behind which are the mouth ends of said pair of clip terminals.

Fig. 3 is a perspective view bracketedly show ing the adaptor as in Fig. 1 but with said casing removed, and showing also a standard electrical plug in course of being advanced toward having its blade terminals entered into the clip terminals of the adaptor.

Fig. 4 is a view like Fig. 3, except that with the parts here shown, the blade terminals of the adaptor are directed away from the observer rather than toward the observer as in Fig. 3; this view also showing the blade terminals of the adaptor in course of being advanced toward insertion in the receptacle of a wall outlet.

Fig. 5 is a perspective view, schematic in so far as is concerned merely a showing in dot and dash lines of the main bulk of an insulation-block like that of the other views, but with here the prong terminals illustrated as projected from one end of said block and the clip terminals projected from the opposite end thereof.

Referring now to the drawings more in detail and first to Figs. 1-4, the adaptor illustrated is provided with a single readily moldable insulation-block l0, variously recessed over both its two opposite long sides, to provide a number of appropriate receptors for the already referred to conductive and contactive parts and the fuse.

The aforesaid pair of blade terminals are designated H, and the foresaid pair of clip terminals are designated I2; the fuse being indicated at I3 and as in the form of a well-known slender cylindrical unit sometimes called a cartridge fuse. As is well-known, this type of fuse has a central glass or otherwise transparent shell portion, capped at opposite ends by metal cups.

For quick mounting and detachment of this fuse in a recess I3", which is of all the recesses present the one of greatest depth, there is projected, from one of the blade terminals H and into one end of said recess l3, a contact for one of the end cups of the fuse and constituted by a thin metal stamping 16 formed to include a pair of parallelly upstanding resilient jaws H5 for releasably clasping said end cup; and into the other end of said recess l3 there is projected a contact for the other end cup of the fuse and constituted by a thin metal stamping ll formed to include a pair of parallelly upstanding resilient jaws H for releasably clasping the end cup lastnamed.

The member is apertured near its end remote from its jaws, and the near blade terminal II in Fig. 3 is matchingly apertured, so that through these apertures a single screw 18 may serve as shown for connecting the parts H and H; as illustrated. As will be noted from the lower part of Fig. 3, a similar arrangement is provided, this including a single screw [8, for connecting the member i? and the near clip terminal l2 in that view.

As shown best in Fig. 4, the near blade terminal H in this view has associated therewith a thin metal stamping 20 contactingly related to said terminal in a manner analogous to the relation of the stamping IE to the other terminal I l, with the first two of the just mentioned parts connected together by a single screw 2!. The same arrangement is provided near the bottom of the side of the block it! seen in Fig. 4 by a thin stamping 22, like the stamping 20, with here again A .erely a sin le screw 23 being employed for connecting those parts. A recess 24, not as deep as, but otherwise similar to, the recess 13 is present in the block l and into which are inserted the end portions of the stampings 20 and 22 which are directed toward each other. Said recess 24 is laterally extended for accommodating a conductor member 25 for connecting stampings 20 and 22 by contact with their said end portions projected into the recess 24. Said conductor member 25 is here indicated as riveted in place, but in the space occupied by it there may be removably positioned, as by use of a screw or the like, a substitute unit comprising a plate-like member partially of insulating material, and partially carrying a fuse link for suitable contact at opposite ends with the end portions of the stampings 20 and 22 projected into the recess 24.

As best illustrated in Figs. 1 and 2, the insulation-block l0 equipped as just above described in connection with Figs. 3 and 4, may be provided with an easily removable fully protective casing, and of a kind to be fabricable at exceedingly small expense and from the use of low-cost mold- The openings 30, 30, seen at the left in Fig. 2, C

are located opposite the blade-terminal-receptor spaces between the reversely bent lengths of the clip terminals 12.

Merely two screws 3| and 32 sufilce for securely yet readily detachably coupling the casing 26 fully protectively relative to the entirety of the adaptor as shown and described in connection with Figs. 3 and 4. Tapped recesses 33 and 34 would then be provided in the insulation block [0 for taking, respectively, the screws 3! and 32.

Thus, with or without the casing 26 in place, but, of course, preferably with the adaptor including such casing, the adaptor may be used as a plug at its blade terminal H in regard to such a wall receptacle as shown at 35 in s, and then a standard plug 35, as one leading from an electrical appliance, may be inserted through the openings 30 for coaction of the blade terminals of said plug with the clip terminals IQ of the adaptor; or the adoptor may be applied at said appliance, by way of its blade terminals H, and a plug like the plug 36 used in connection with the adoptors clip terminals l2, with said plug wired to any direct or intermediate source of current supply.

Referring to the modification shown in Fig. 5, this differs essentially from the adaptor of Figs. 1-4, in that the adaptor of Fig. 5, with a single elongate insulation block [0' substantially like the block It, so carries its two pairs of terminals that the two blade terminals 1 l project from one end of said block and the two clip terminals [2 are at the other end of said block; the plug being of course recessed in accordance with the princi ples explained in connection with Figs. 3 and l. In Fig. 5, the fuse is indicated l3, and the parts to which are applied reference numerals with primes added correspond, respectively, to the parts to which have been applied the same reference numerals without primes. Here, however, it will be noted, the jaws I6 are integral with one of the blade terminals l I, and the jaws ll are integral with one of the clip terminals l2. It will also be noted that these clip terminals are provided by a bending over of their stampings in a different manner from that characteristic of the clip terminals l2, that is, with the bights of the clip terminals 12' extending longitudially of the stampings of which they are made.

The stamping used for providing one of the blade terminals l l and the jaws 16 is somewhat Z bent as indicated at 31, to limit endwise movement of the fuse IS in one direction; while, to provide a similar stop for said fuse against movement in the opposite direction, a small tongue 33 is struck from the stamping which includes the jaws H and one of the clip terminals [2.

It will also be noted that here the other bladeterminal II and the other clip terminal l2 shown as integral parts of a single stamping. In that case, merely a single screw 39 wool: .iflice securely to position said single stamping in the provided recess in a side of the block it. As for the stamping 31, and the stamping including the tongue 38, these, together with the fuse [3, would be placed in the provided recess in the opposite side of the block l0.

With a screw 40 used to fix the stamping 3'! in position, the casing next referred to could provide a suitable recess therein for retaining the stamping which includes the tongue 38 properly in place in its portion of the recess last referred to. A single casing constructed according to the principles used in providing the casing 25 may be and desirably is included in an adaptor of the hind shown in Fig. 5.

While I have illustrated and described the preferred embodiments of my invention, it is to be understood that I do not limit myself to the precise construct-ions herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claims.

Having thus described my invention, what I claim as new, and desire to secure by United States Letters Patent is:

1. In combination, an insulation block having transversely extended pairs of recesses in its opposed side faces and front and rear faces, said block having longitudinally extended recesses in each of its opposed side faces joining the recesses of each pair of recesses, elongated blade terminals positioned in one recess of each pair of recesses adjacent one end of said block and having end portions projected from the rear face of said block for insertion into an outlet receptacle, U- shaped clip terminals positioned in the other recess of each pair of recesses and having portions extended from the rear face of said block, said recesses housing said U-shaped clip terminals being open to the front face of said insulation block for insertion of the conductor blades of a plug to make electrical contact with said clip terminals, conductor means in said longitudinally extended recesses and connected between the respective blade terminals and clip terminals, a cover of insulation material closing said recesses retaining said blade terminals, said clip terminals and said conductor means in position in said recesses, said cover comprising walls extended along and co-extensive with the recessed side faces of said insulation block, a bridging element integrally formed with the rear edges of said walls and extended across the rear face of said insulation block, and means releasably securing said walls and bridging element to said insulation block, said bridging element being narrow and located to extend over and cover the portions of said clip terminals which project from the rear face of said insulation block.

2. In combination, an insulation block having transversely extended pairs of recesses in its opposed side faces and front and rear faces, said block having longitudinally extended recesses in each of its opposed side faces joining the recesses of each pair of recesses, elongated blade terminals positioned in one recess of each pair of recesses adjacent one end of said block and having end portions projected from the rear face of said block for insertion into an outlet receptacle, U- shaped clip terminals positioned in the other recess of each pair of recesses and having portions extended from the rear face of said block, said recesses housing said U-shaped clip terminals being open to the front face of said insulation block for insertion of the conductor blades of a plug to make electrical contact with said clip terminals, conductor means in said longitudinally extended recesses and connected between the respective blade terminals and clip terminals, a cover of insulation material closing said recesses retaining said blade terminals, said clip terminals and said conductor means in position in said recesses, said cover comprising walls extended along and coextensive with the recessed side faces of said insulation block, a bridging element integrally formed with the rear edges of said walls and extended across the rear face of said insulation block, and means releasably securing said walls and bridging element to said insulation block, said bridging element being narrow and located to extend over and cover the portions of said clip terminals which project from the rear face of said insulation block, said bridging element having cavities in its inner face into which the projected portions of said clip terminals extend.

HYMAN SHAPIRO.

REFERENCES CITED The following references are of record in the file of this :patent:

UNITED STATES PATENTS Number Name Date 1,633,025 Kranz June 21, 1927 1,650,421 Brown Nov. 22, 1927 1,863,824 Barnett June 21, 1932 1,990,176 Fried Feb. 5, 1935 2,431,999 Engelhardt Dec. 2, 1947 

